A crusher is known which includes a casing and a crushing means (Patent Document 1 and Patent Document 2). The casing includes an upper loading opening into which an object to be crushed is loaded, and a lower discharge opening from which a crushed object is discharged. The crushing means is disposed in a crushing chamber within the casing.
In other words, in a crusher described in Patent Document 1, as shown in FIG. 17, a discharge plate 5 is placed in a lower discharge opening 3 of a casing 1. The discharge plate 5 has a plurality of discharge holes 4. A crushing chamber 6 is formed by inner surfaces of the plate 5 and the casing 1. A crushing means 7 is disposed in the crushing chamber 6. The crushing means 7 includes hammer members 9, fixed blades 10, and the like. The hammer members 9 are arranged on a circular rotating plate 8 at a predetermined pitch along a circumferential direction. The fixed blades 10 are fixed onto the inner surface of the crushing chamber 6 (inner surface of the casing 1). The fixed blades 10 are arranged along a circular arc surface corresponding to a circular trajectory followed by the front end edge of the hammer members 9 during rotation.
Therefore, when an object to be crushed is loaded into the upper loading opening 2 of the casing 1 and fed to the crushing chamber 6, as a result of rotation of the hammer members 9, the object to be crushed is crushed by coordinated operation between the hammer members 9 and the fixed blades 10. The crushed object is then discharged outside from the holes on the discharge plate 5 at the lower discharge opening 3.    Patent Document 1: Japanese Patent Application Laid-open No. Heisei 8-117634    Patent Document 2: Japanese Patent Application Laid-open No. 2001-153149